JHDM2: The JHDM2 family of proteins have orthologues from flies to humans; they possess JmjC and modified zinc finger domains. The mammalian JHDM2 family is comprised of four human proteins: hairless (HR), JHDM2A, JHDM2B, and JHDM2C. HR was originally identified in mice, and its mutation results in universal congenital alopecia. Mutation in its human homologue also causes hereditary alopecia. HR is expressed in the skin and the brain, where it probably functions as a corepressor of the thyroid hormone receptor. (1)